One of the most notable features of Nessus 4 is the ability to create custom XSLT reports based on your scan results. Nessus now also supports a fully multi-threaded scanning engine, which is improves performance and decrease your scan times.

The following is a highlight of some of the features and improvements:

Nessus engine

Uses the same engine on Windows and Unix-based systems for a unified experience on all platforms and more consistent results

Local and remote port scanners can now be combined. For example, if you select the Nessus SYN scanner and the netstat WMI portscanner , Nessus will try to log in via WMI to enumerate the ports first, then to fall back to the SYN scanner

The TCP SYN port scanner has been rewritten entirely and operates the same between Windows and Unix-based systems

Native UDP port scanner (ProfessionalFeed Only).

Compliance checking

The database compliance checks can now log into MSSQL over SSL

The PCI-DSS plugins are now fully supported.

NASL (Nessus Attack Scripting Language)

Added support for Perl Compatible Regular Expressions (PCRE) to NASL

NASL scripts can now share results between hosts via a global knowledgebase